Anyone having problems receiving texts with Qtel?

Hi i would like to know if anyone else has the same problem receiving texts.

Some times i can not receive texts from some people here in Qatar.

In the beginning i thought that i had a problem with my iphone.

Then i realised that its not my fault, since its not possible sometimes to receive and sometimes can not receive from the same people.

I also dont receive texts from my home Greece (again not always).

I called Qtel and they told me that there is not their fault and that my inbox might be full. That was impossible with iphone. Especially since i keep receiving texts from other people. My suspicions for Qtel grow bigger when i reset my network settings and the problems was solved for a whlie. But it keeps happening again.

Does anyone have any ideas?